The present invention relates to a method for manufacturing cut tobacco by shredding leafy tobacco material and a manufacturing system therefor.
Usually, leafy tobacco material is conditioned before a shredding process. Thereafter, an additive (so-called first flavoring) is added to the leafy tobacco material, the additive containing a perfume, humectant, water, etc. A first object of the addition of this additive is to improve the flavor of the tobacco material, and a second object is to soften the tobacco material, thereby preventing fracture of cut tobacco during the subsequent shredding process.
After the shredding process, the cut tobacco is dried, and a top flavoring (so-called second flavoring) is added to the cut tobacco. The top flavoring contains a perfume as its principal ingredient, depending on the brand of cigarettes to be manufactured from the cut tobacco.
The aforesaid additive cannot easily permeate the leafy tobacco material, and the perfume component in the additive is volatile. Thus, the additive remaining in the tobacco material after the shredding process or drying process is little.
In order to keep the residual quantity of the additive in the cut tobacco at a desired level after the cut tobacco drying process, therefore, the additive must be added in plenty to the leafy tobacco material, so that the consumption of the additive increases.
If the addition of the additive to the tobacco material is too much, however, the perfume component of the additive excessively adheres to a cutter of a shredder during the shredding process for the tobacco material. Accordingly, the cutter becomes so dull that it cannot satisfactorily shred the tobacco material, and the maintenance of the cutter takes much time.
If the residual additive quantity of the cut tobacco after the shredding process is too small, on the other hand, the cut tobacco is dried excessively in the drying process. Consequently, the cut tobacco cannot maintain its required taste and flavor, and its quality lowers.
The object of the present invention is to provide a manufacturing method and a manufacturing system, capable of securing the quality of cut tobacco after a drying process without failing to lower the consumption of additives and considerably improving the expansion of the cut tobacco.
In order to achieve the above object, a manufacturing method according to the present invention comprises a process for conditioning leafy tobacco material to a given water content, a process for providing the conditioned tobacco material with a first liquid additive containing a humectant, a process for shredding the tobacco material provided with the first additive, thereby obtaining cut tobacco, a process for providing the cut tobacco with a second liquid additive containing a perfume and adjusting the water content of the cut tobacco to a pre-drying water content, a process for drying the cut tobacco having the pre-drying water content to a target water content, and a process for providing the dried cut tobacco with a third additive containing a perfume.
According to the manufacturing method described above, the leafy tobacco material is first provided with the first additive that consists mainly of the humectant, so that the unshredded tobacco material is soft. Accordingly, the cut tobacco can be prevented from being fractured as the tobacco material is shredded.
Since the second additive is added to the cut tobacco, the cut tobacco efficiently absorbs the second additive that contains the perfume. If the cut tobacco is dried thereafter, the residual quantity of the second additive in the cut tobacco, that is, the residual quantity of the perfume component in the second additive, can be kept sufficient. In consequence, the consumption of the second additive can be reduced without failing to maintain the quality of the cut tobacco.
Preferably, the pre-drying water content and the target water content are adjusted to the range of 17 to 35% by weight and the range of 9 to 14% by weight of the cut tobacco, respectively, and a deviation of 5 to 25% by weight in terms of the water content is secured between the pre-drying water content and the target water content.
The deviation of the aforesaid range between the pre-drying water content and the target water content causes a sufficient quantity of water to evaporate from the cut tobacco, thereby subjecting the cut tobacco to crimpling or so-called curls, during a drying process for the cut tobacco. The curls enhance the expansion of the cut tobacco, so that the filling efficiency for the cut tobacco in cigarettes increases.
Preferably, in consideration of the maintenance of the quality of the cut tobacco, the cut tobacco drying process is carried out at a drying temperature of 80 to 300xc2x0 C. In order to curl the cut tobacco with stability, moreover, the cut tobacco drying process is carried out by flash drying at 140xc2x0 C. or more, and more specifically, at 140 to 280xc2x0 C. Since the cut tobacco is dried in a short time according to the aforesaid flash drying, water in a firmly coupled state in the cut tobacco is quickly evaporated from the cut tobacco, whereby the formation of curls of the cut tobacco is promoted.
The aforesaid tobacco material may contain one brand selected from laminar tobaccos of the Bright brand and the Oriental brand. Further, the tobacco material may be a mixture of laminar tobaccos of the Bright brand and the Oriental brand.
The first additive may further contain a perfume. In this case, the perfume may be the same perfume that the second additive contains or a different one.
The perfume of the first additive serves to improve the flavor and taste of the cut tobacco. The addition of the perfume to the first additive is suited for the tobacco material of the Burley brand or the like that contains less natural saccharide than the tobacco materials of the Bright brand, Oriental brand, etc. do, and can improve the flavor and taste of cut tobacco that is obtained from the tobacco material of the Burley brand.
Preferably, moreover, the method further comprises a curing process for the tobacco material between the first additive providing process and the tobacco material shredding process. In this case, absorption of the first additive by the tobacco material can be promoted.
The manufacturing method of the present invention may further comprise a plurality of procedures of processing for individually carrying out the first additive providing process and the preceding processes for each of tobacco materials of a plurality of brands and a process for mixing the tobacco materials obtained according to the individual procedures of processing before the tobacco material shredding process.
In the case where the tobacco materials include tobacco materials of three brands, the Bright brand, Oriental brand, and Burley brand, a providing process for the first additive can be carried out together in the procedures of processing for individually processing the tobacco materials of the Bright brand and the Oriental brand. In this case, the same first additive is added to the tobacco materials of the Bright brand and the Oriental brand.
The manufacturing method of the present invention may further comprise a plurality of procedures of processing for individually carrying out the drying process and the preceding processes for each of tobacco materials of a plurality of brands and a process for mixing the tobacco materials obtained according to the individual procedures of processing before the third additive providing process.
In the case where the tobacco materials include tobacco materials of the Bright brand, Oriental brand, and Burley brand, the first additive providing process and the subsequent processes may be carried out in common in the procedures of processing for individually processing the tobacco materials of the Bright brand and the Oriental brand.
Further, the present invention also provides a manufacturing system for carrying out the manufacturing method described above. This manufacturing system comprises a conditioning apparatus for conditioning leafy tobacco material to a given water content, a first providing apparatus for providing the conditioned tobacco material with a first liquid additive containing a humectant, a shredder for shredding the tobacco material received from the first providing apparatus, thereby obtaining cut tobacco, a second providing apparatus for providing the cut tobacco received from the shredder with a second liquid additive containing a perfume and adjusting the water content of the cut tobacco to a pre-drying water content, and a dryer for drying the cut tobacco received from the second providing apparatus to a target water content.
Preferably, the manufacturing system further comprises a storehouse for storing the tobacco material provided with the first additive to cure the same before the tobacco material is fed to the shredder.
In order to curl the cut tobacco with stability, the dryer should preferably be a flash dryer.